Please help! Been stuck on this for hours Solve the inequality. Express your answer in interval form. (If there is no solution, enter NO SOLUTION.) 2 ≤ |x^2 − 4| < 4
Answer:
(-√8, -√6] ∪ [-√2, 0) ∪ (0, √2] ∪ [√6, √8)
Step-by-step explanation:
The inequality resolves into 4 inequalities. There are 4 intervals in the solution.
Starting at the left, for the absolute value argument less than 0:
2 ≤ -(x^2 -4) . . . . . . . for x^2 -4 ≤ 0
2 ≤ -x^2 +4
-2 ≤ -x^2
2 ≥ x^2 . . . . . . . . . . consistent with the above 4 ≥ x^2
-√2 ≤ x ≤ √2 . . . . . square root; may be limited by other constraints
For the absolute value argument greater than 0:
2 ≤ x^2 -4 . . . . . . . for x^2 -4 ≥ 0
6 ≤ x^2 . . . . . . . . . .consistent with x^2 ≥ 4
-√6 ≥ x ∪ x ≤ √6 . . . . take the square root
__
The inequality on the right can be written as the compound inequality ...
-4 < x^2 -4 < 4
0 < x^2 < 8 . . . . . add 4
0 < |x| < √8 . . . . take the square root
This resolves to ...
-√8 < x < 0 ∪ 0 < x < √8
__
So, the solution set is the set of values of x that satisfy these restrictions on x:
-√2 ≤ x ≤ √2
x ≤ -√6 ∪ x ≤ √6
-√8 < x < 0 ∪ 0 < x < √8
That is a collection of 4 intervals:
(-√8, -√6] ∪ [-√2, 0) ∪ (0, √2] ∪ [√6, √8)
_____
You may be expected to write √8 as 2√2.
__
These intervals are the portions of the red curve that lie between the two horizontal lines. The points on the upper (dashed) line are not part of the solution set. The points on the lower (solid) line are part of the solution set.
i have a daily allowance of 70grm but have only used 48 what percentage do i have left
Answer:
You have 31.43% of your allowance left.
Step-by-step explanation:
This question can be solved using a rule of three.
Your initial amount, of 70, is 100%.
The remaining amount, of 70 - 48 = 22, is x%. So
70 - 100%
22 - x%
[tex]70x = 100*22[/tex]
[tex]x = \frac{100*22}{70}[/tex]
[tex]x = 31.43[/tex]
You have 31.43% of your allowance left.
What is the area of the rhombus?
Answer: 24 square units
Explanation: The diagonals are 4+4 = 8 and 3+3 = 6 units long. Multiply the diagonals to get 8*6 = 48. Then divide this in half to get 48/2 = 24.
An alternative is to find the area of one smallest triangle, and then multiply that by 4 to get the total area of the rhombus. You should find the area of one smallest triangle to be 0.5*base*height = 0.5*4*3 = 6, which quadruples to 24.
X and Y are both standard normal random variables (mean = 0, standard deviation = 1), statistically independent of each other. Using the DATA IN THE ATTACHED FILE, estimate the probability that X and Y are both positive and that their sum is less or equal to 1. This probability is
Answer:
The probability that X and Y are both positive and that their sum is less or equal to 1 0.64.
Step-by-step explanation:
It is provided that the random variables X and Y follows a standard normal distribution.
That is, [tex]X,Y\sim N(0, 1)[/tex]
It is also provided that the variables X and Y are statistically independent of each other.
Compute the probability that X and Y are both positive and that their sum is less or equal to 1 as follows:
The mean and standard deviation of X + Y are:
[tex]E(X+Y)=E(X)+E(Y)=0+0=0\\\\SD(X+Y)=\sqrt{V(X)+V(Y)+2Cov(X,Y)}=\sqrt{1+1+0}=\sqrt{2}[/tex]
The probability is:
[tex]P(X+Y\leq 1)=P(X+Y<1-0.50)\ [\text{Apply continuity correction}]\\[/tex]
[tex]=P(X+Y<0.50)\\\\=P(\frac{(X+Y)-E(X+Y)}{SD(X+Y)}<\frac{0.50-0}{\sqrt{2}})\\\\=P(Z<0.354)\\\\=0.63683\\\\\approx 0.64[/tex]
*Use the z-table.
Thus, the probability that X and Y are both positive and that their sum is less or equal to 1 0.64.
A scale drawing of a rectangular painting has a scale factor of 1:4 which statements are true
Answer:
object have been reduced by a factor of 4 on paper or the drawing have been increased by a factor of 4 on land .
Step-by-step explanation:
What a scale factor of 1:4 means.
Simply it means that the reals size of the object on land have been reduced in the drawing in the paper.
Now for scale factor of 1:4 in particular it means that the object have been reduced by a factor of 4 on paper or the drawing have been increased by a factor of 4 on land .
Example if the drawing has measurements of 4 inches on paper, then on land it will be 16 inches
Solve 23 - Q >-3(2-6)
Answer:
q < 11
Step-by-step explanation:
Distribute the -3
23 - q > 12
Add q and subtract 12
q < 11
Step-by-step explanation:
the answer is
q<11
23-q>12
which one of the following solids produces these two-dimensional shape when sliced horizontally?
Answer:
D
Step-by-step explanation:
find the vector reciprocal to set. a= i+2j+2k, b= 2i+3j+k, c= i-j-2k
Answer:
I just do a' as a sample. You calculate b' and c'
Step-by-step explanation:
[tex]a'=\frac{b\times c}{a\bullet (b\times c)}, b' = \frac{c\times a}{a\bullet (b\times c)}, c' = \frac{a\times b}{a\bullet (b\times c)}[/tex]
Now, calculate b x c
[tex]\left[\begin{array}{ccc}i&j&k\\2&3&1\\1&-1&-2\end{array}\right] =<-5, 5,-5>[/tex]
[tex]a'=\frac{<-5,5,-5>}{<1, 2, 2>\bullet <-5, 5,-5>}=\frac{<-5, 5, -5>}{-5} =<1,-1,1>[/tex]
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answer:
its b I belive
Step-by-step explanation:
Answer:
The answer is B.
Step-by-step explanation:
In order to find (f-g)(x), you have to subtract g(x) from f(x) :
[tex]f(x) = {3}^{x} + 10[/tex]
[tex]g(x) = 2x - 4[/tex]
[tex](f - g)(x) = {3}^{x} + 10 - 2x - ( - 4)[/tex]
[tex](f - g)(x) = {3}^{x} + 10 - 2x + 4[/tex]
[tex](f - g)(x) = {3}^{x} - 2x + 14[/tex]
If a number is added to the numerator of 7/9 and the same number is subtracted from the denominator, the result is 3. Find the number.
Answer:
5
Step-by-step explanation:
[tex]\frac{7+x}{9-x}=3\\ 7+x = 3(9-x)\\7+x=27-3x\\x+3x=27-7\\4x=20\\x=5[/tex]
What is the MEDIAN of this data?
Answer:
I think the median is 7
if it is not im so sorry
The median of the data is 7.
please see the attached picture for full solution
Hope it helps
Good luck on your assignment
The HCF of two numbers is 11, and their L.C.M is 368. If one number is 64, then the other number is
Answer:
63.25 not an integer
Step-by-step explanation:
HCF(a,b)*LCM(a,b)=ab
11*368=64*x
x=11*368/64
x=63.25 not an integer, one of the given numbers must be incorrect
but you may use this method to find it yourself
What is the general form of this equation:
The line passes through the point (-2,4) with a slope -2/3
Answer: y= -2/3 + 8/3
Step-by-step explanation:
-2/3 is the slope so you just need the y-intercept to write the equation in general form or slope intercept form
4= -2/3(-2) +b
4 = 4/3 + b
-4/3 -4/3
b= 8/3
general form is y= -2/3 + 8/3
is 7.68 bigger than 7.680
Answer:
literally 7.68=7.680
Express loga 6 + loga 70 as a single logarithm
Answer:
logₐ(420)
Step-by-step explanation:
Answer:
The answer is
[tex] log_{a}(420) [/tex]
Step-by-step explanation:
You have to use Logarithm Law,
[tex] log_{a}(b) + log_{a}(c) ⇒ log_{a}(b \times c) [/tex]
* Take note, number b and c can only be multiplied when they have the same base, a
So for this question :
[tex] log_{a}(6) + log_{a}(70) [/tex]
[tex] = log_{a}(6 \times 70) [/tex]
[tex] = log_{a}(420) [/tex]
In a class of 30 students, there are four more girls than boys. a)Using x as the number of boys, write down an equation b)Solve the equation and find the number of girls in the class.
easy claps!!
Answer: 30=2x+4 and there are 17 girls in the class.
Step-by-step explanation: if x+4=[total girls] and x=[total boys] and 30=[total kids], then x+4+x = 2x+4 = [total kids], since total kids id 30 then our equation is 30 = 2x + 4 and x= 13boys so 30-13= 17girls.
It's BASIC prealgebra so you should probably practice bit more with linear equations!
For which x is f(x)?=-3
-7
-4
4
5
Answer:
B.
✔ -4
Step-by-step explanation:
E 2021
What is 40% of 160?
Answer:
40% of 160 is 64
Step-by-step explanation:
You can easily find the answer in one step, just multiplying the whole (160) by the percentage (40) divided by 100.
So, 40% of 160 = 160 × 0.4 = 64.
Answer:
64
Step-by-step explanation:
You first have to subtract 40% from 160 and then you subtract that amount with is 96 from 160 and you get your answer 64
someone pls help me ! i rlly need help
Answer:
Option D is the correct answer.
Step-by-step explanation:
Coefficients od dividend = (4, - 17, - 15)
Dividend [tex]=4x^2 - 17x - 15[/tex]
Divisor x = 5 =>x-5= 0
Coefficients of Quotient = (4, 3)
Quotient [tex]=4x + 3[/tex]
Remainder = 0
Since,
[tex] Dividend = Divisor \times quotient + Remainder\\
\therefore 4x^2 - 17x - 15 = (x - 5)\times (4x + 3) +0 \\
\therefore 4x^2 - 17x - 15 = (x - 5)\times (4x + 3) \\
\therefore( 4x^2 - 17x - 15) \div (x - 5) = (4x + 3)
[/tex]
Life tests performed on a sample of 13 batteries of a new model indicated: (1) an average life of 75 months, and (2) a standard deviation of 5 months. Other battery models, produced by similar processes, have normally distributed life spans. The 98% confidence interval for the population mean life of the new model is _________. Group of answer choices
Answer:
(71.28, 78.72)
Step-by-step explanation:
We have the following information from the statement:
mean (m) = 75
sample standard deviation (sd) = 5
Sample size (n) = 13
Significance level (alpha) = 1 - 0.98 = 0.02
Degrees of freedom for t-d (df) = n - 1 = 13 - 1 = 12
The critical value would be:
t (alpha / 2) / df = T (0.01) / 12 = 2,681 (this for the table)
Margin of error equals:
E = t (alpha / 2) / df * sd / n ^ (1/2), replacing:
E = 2,681 * 5/13 ^ (1/2)
E = 3.72
Therefore, the interval of 98% confidence interval would be:
75 + 3.72 = 78.72
75 - 3.72 = 71.28
(71.28, 78.72)
Wisconsin Public Radio wants to duplicate a survey conducted in 2011 that found that 68% of adults living in Wisconsin felt that the country was going in the wrong direction. How many people would need to be surveyed for a 90% confidence interval to ensure the margin of error would be less than 3%? Be sure to show all your work and round appropriately
Answer:
655 people would need to be surveyed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
In this question, we have that:
[tex]\pi = 0.68[/tex]
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
90% confidence level
So [tex]\alpha = 0.1[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].
How many people would need to be surveyed for a 90% confidence interval to ensure the margin of error would be less than 3%?
We need to survey n adults.
n is found when M = 0.03. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.03 = 1.645\sqrt{\frac{0.68*0.32}{n}}[/tex]
[tex]0.03\sqrt{n} = 1.645\sqrt{0.68*0.32}[/tex]
[tex]\sqrt{n} = \frac{1.645\sqrt{0.68*0.32}}{0.03}[/tex]
[tex](\sqrt{n})^{2} = (\frac{1.645\sqrt{0.68*0.32}}{0.03})^{2}[/tex]
[tex]n = 654.3[/tex]
Rounding up
655 people would need to be surveyed.
In a manufacturing process, a machine produces bolts that have an average length of 5 inches with a variance of .08. If we randomly select five bolts from this process, what is the standard deviation of the sampling distribution of the sample mean
Answer:
[tex] \bar X \sim N(\mu , \frac{\sigma}{\sqrt{n}})[/tex]
And replacing:
[tex] \mu_{\bar X}= 5[/tex]
And the deviation:
[tex] \sigma_{\bar X}= \frac{0.283}{\sqrt{5}}= 0.126[/tex]
And the distribution is given:
[tex] \bar X \sim N(\mu= 0.08, \sigma= 0.126)[/tex]
Step-by-step explanation:
For this case we have the following info given :
[tex] \mu= 5. \sigma^2 =0.08[/tex]
And the deviation would be [tex] \sigma = \sqrt{0.08}= 0.283[/tex]
For this case we select a sample size of n = 5 and the distirbution for the sample mean would be:
[tex] \bar X \sim N(\mu , \frac{\sigma}{\sqrt{n}})[/tex]
And replacing:
[tex] \mu_{\bar X}= 5[/tex]
And the deviation:
[tex] \sigma_{\bar X}= \frac{0.283}{\sqrt{5}}= 0.126[/tex]
And the distribution is given:
[tex] \bar X \sim N(\mu= 0.08, \sigma= 0.126)[/tex]
Help, please. I dont really understand
Answer:
We can eliminate the second and third options because marking something up doesn't result in a number less than the original. Since we are told to select 3 options and there are 3 answer choices left we select the first, fourth, and fifth statements.
the cost of a leather coat went up from $75 to $90. what is the percent increase?
Answer:
20%
Step-by-step explanation:
The increase is ...
$90 -75 = $15
As a percentage of the original price, that is ...
$15/$75 × 100% = 0.20×100% = 20%
The increase was 20%.
at an ice cream shop, thirty cups of ice cream costs $105. what is the cost of one cup of ice cream? what is the cost of 18 cups of ice cream??
Hey there! :)
Answer:
Price per cup: $3.5
Price for 18 cups: $63.
Step-by-step explanation:
To find the cost of a single cup of ice cream, we can set up an equation where 'x' equals the price of a cup of ice cream.
30x = 105
Divide both sides by 30:
x = $3.5.
To find the cost of 18 cups, simply multiply this price by 18:
18 × 3.5 = $63 dollars. This is the price for 18 cups of ice cream.
Distribute and simplify these radicals. square root of 60
Answer:
2 sqrt(15)
Step-by-step explanation:
sqrt(60) = sqrt(4*15) = 2 sqrt(15)
The hypotenuse of a right triangle is 95 inches long. One leg is 4 inch(es) longer than the other. Find the lengths of the legs of the triangle. Round your answers to the nearest tenth of an inch.
Answer:
65.1 and 69.1
Step-by-step explanation:
a^2+b^2=c^2
c=95
b=a+4
Solve for a^2+(a+4)^2=95^2
a=65.1
b=a+4=69.1
Answer:
65.1 and 69.1
Step-by-step explanation:
c² = a² + b²
c= 95
a - one leg
b= (a + 4) - second leg
95² = a² + (a + 4)²
9025 = a² + a² + 2*4a + 16
2a² + 8a - 9009 = 0
[tex]a= \frac{-b +/-\sqrt{b^2 - 4ac} }{2a} \\\\a = \frac{-8 +/-\sqrt{8^2 - 4*2*9009} }{2*2} \\\\a=65.1 \ and \ a=- 69.1[/tex]
A leg length can be only positive. a = 65.1
b = 65.1 + 4 = 69.1
A rocket is launched from a tower. The height of the rocket, y in feet, is related to the time after launch, x in seconds, by the given equation. Using this equation, find the maximum height reached by the rocket , to the nearest 100th of a foot. y=-16x^2+230x+112
Answer:
The maximum height reached by the rocket is of 938.56 feet.
Step-by-step explanation:
The height y, after x seconds, is given by a equation in the following format:
[tex]y(x) = ax^{2} + bx + c[/tex]
If a is negative, the maximum height is:
[tex]y(x_{v})[/tex]
In which
[tex]x_{v} = -\frac{b}{2a}[/tex]
In this question:
[tex]y(x) = -16x^{2} + 230x + 112[/tex]
So
[tex]a = -16, b = 230, c = 112[/tex]
Then
[tex]x_{v} = -\frac{230}{2*(-16)} = 7.1875[/tex]
[tex]y(7.1835) = -16*(7.1835)^{2} + 230*7.1835 + 112 = 938.56[/tex]
The maximum height reached by the rocket is of 938.56 feet.
Find f. f ''(θ) = sin(θ) + cos(θ), f(0) = 2, f '(0) = 1 f(θ) =
Answer:
[tex]f(theta)=sin(theta) - cos(theta)[/tex] + C
This is my first time doing a double integral, so im only 90% sure in my answer
Step-by-step explanation:
You pretty much want to take the double integral of sinx + cosx
The anti-derivative of sinx = -cosx
The anti-derivative of cosx = sinx
So f' = -cosx + sinx
Now lets take the integral of f':
The anti-derivative of -cosx = sinx
The anti-derivative of sinx = -cosx
So, f(x) = sinx - cosx
============================================================
Work Shown:
I'll use x in place of theta since its easier to type on a keyboard.
f '' (x) = sin(x) + cos(x)
f ' (x) = -cos(x) + sin(x) + C ..... integrate both sides; dont forget the plus C
f ' (0) = 1
f ' (0) = -cos(0) + sin(0) + C
-cos(0) + sin(0) + C = 1
-1 + 0 + C = 1
C = 1+1
C = 2
So,
f ' (x) = -cos(x) + sin(x) + C
turns into
f ' (x) = -cos(x) + sin(x) + 2
----------------------------
Now integrate both sides of the first derivative to get the original f(x) function
f ' (x) = -cos(x) + sin(x) + 2
f(x) = -sin(x) - cos(x) + 2x + D .... apply integral; D is some constant
f(0) = -sin(0) - cos(0) + 2(0) + D
f(0) = 0 - 1 + 0 + D
f(0) = D - 1
f(0) = 2
D-1 = 2
D = 2+1
D = 3
We have f(x) = -sin(x) - cos(x) + 2x + D update to f(x) = -sin(x) - cos(x) + 2x + 3
----------------------------
So f '' (x) = sin(x) + cos(x) becomes f(x) = -sin(x) - cos(x) + 2x + 3 when f(0) = 2 and f ' (0) = 1
The last step is to replace every x with theta so that we get back to the original variable.
f(x) = -sin(x) - cos(x) + 2x + 3 turns into f(θ) = -sin(θ) - cos(θ) + 2θ + 3
Which explains how to find the quotient of the division below? - 3 1/3 divided by 4/9 Write Negative 3 and one-third as Negative StartFraction 13 over 3 EndFraction, and find the reciprocal of StartFraction 4 over 9 EndFraction as StartFraction 9 over 4 EndFraction. Then, rewrite Negative 3 and one-third divided by StartFraction 4 over 9 EndFraction as Negative StartFraction 13 over 3 EndFraction times StartFraction 9 over 4 EndFraction. The quotient is Negative 9 and three-fourths. Write Negative 3 and one-third as Negative StartFraction 10 over 3 EndFraction, and find the reciprocal of StartFraction 4 over 9 EndFraction as StartFraction 9 over 4 EndFraction. Then, rewrite Negative 3 and one-third divided by StartFraction 4 over 9 EndFraction as Negative StartFraction 10 over 3 EndFraction times StartFraction 9 over 4 EndFraction. The quotient is Negative 7 and StartFraction 6 over 12 EndFraction = Negative 7 and one-half. Write Negative 3 and one-third as Negative StartFraction 9 over 3 EndFraction. Then, rewrite Negative 3 and one-third divided by StartFraction 4 over 9 EndFraction as Negative StartFraction 9 over 3 EndFraction times StartFraction 4 over 9 EndFraction. The quotient is Negative 1 and one-third. Write Negative 3 and one-third as Negative StartFraction 10 over 3 EndFraction. Then, rewrite Negative 3 and one-third divided by StartFraction 4 over 9 EndFraction as Negative StartFraction 10 over 3 EndFraction times StartFraction 4 over 9 EndFraction. The quotient is Negative 1 and StartFraction 13 over 27 EndFraction = Negative 1 and StartFraction 13 over 27 EndFraction
Answer:
The answer is D
Step-by-step explanation:
Answer:
A
Step-by-step explanation: